﻿using System.Text;

namespace Shipeng.Util.Helper
{
    public static class HideSensitiveInfoHelper
    {
        /// <summary>
        /// 隐藏敏感信息
        /// </summary>
        /// <param name="info"> 信息实体 </param>
        /// <param name="left"> 左边保留的字符数 </param>
        /// <param name="right"> 右边保留的字符数 </param>
        /// <param name="basedOnLeft"> 当长度异常时，是否显示左边 </param>
        /// <returns> </returns>

        public static string HideSensitiveInfo(this string info, int left, int right, bool basedOnLeft = true)

        {
            if (string.IsNullOrEmpty(info))

            {
                return "";
            }

            StringBuilder sbText = new StringBuilder();

            int hiddenCharCount = info.Length - left - right;

            if (hiddenCharCount > 0)

            {
                string prefix = info.Substring(0, left), suffix = info.Substring(info.Length - right);

                sbText.Append(prefix);

                for (int i = 0; i < hiddenCharCount; i++)

                {
                    sbText.Append("*");
                }

                sbText.Append(suffix);
            }
            else

            {
                if (basedOnLeft)

                {
                    if (info.Length > left && left > 0)

                    {
                        sbText.Append(info.Substring(0, left) + "****");
                    }
                    else

                    {
                        sbText.Append(info.Substring(0, 1) + "****");
                    }
                }
                else

                {
                    if (info.Length > right && right > 0)

                    {
                        sbText.Append("****" + info.Substring(info.Length - right));
                    }
                    else

                    {
                        sbText.Append("****" + info.Substring(info.Length - 1));
                    }
                }
            }

            return sbText.ToString();
        }

        /// <summary>
        /// 隐藏敏感信息
        /// </summary>
        /// <param name="info"> 信息 </param>
        /// <param name="sublen"> 信息总长与左子串（或右子串）的比例 </param>
        /// <param name="basedOnLeft"> 当长度异常时，是否显示左边，默认true，默认显示左边 </param>
        /// <code>true </code>
        /// 显示左边，
        /// <code>false </code>
        /// 显示右边
        /// <returns> </returns>

        public static string HideSensitiveInfo(this string info, int sublen = 3, bool basedOnLeft = true)

        {
            if (string.IsNullOrEmpty(info))

            {
                return "";
            }

            if (sublen <= 1)

            {
                sublen = 3;
            }

            int subLength = info.Length / sublen;

            if (subLength > 0 && info.Length > (subLength * 2))

            {
                string prefix = info.Substring(0, subLength), suffix = info.Substring(info.Length - subLength);

                return prefix + "****" + suffix;
            }
            else

            {
                if (basedOnLeft)

                {
                    string prefix = subLength > 0 ? info.Substring(0, subLength) : info.Substring(0, 1);

                    return prefix + "****";
                }
                else

                {
                    string suffix = subLength > 0 ? info.Substring(info.Length - subLength) : info.Substring(info.Length - 1);

                    return "****" + suffix;
                }
            }
        }

        /// <summary>
        /// 隐藏邮件详情
        /// </summary>
        /// <param name="email"> 邮件地址 </param>
        /// <param name="left"> 邮件头保留字符个数，默认值设置为3 </param>
        /// <returns> </returns>
        public static string HideEmailDetails(this string email, int left = 3)

        {
            if (string.IsNullOrEmpty(email))

            {
                return "";
            }
            if (System.Text.RegularExpressions.Regex.IsMatch(email, @"\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*"))//如果是邮件地址

            {
                int suffixLen = email.Length - email.LastIndexOf('@');

                return HideSensitiveInfo(email, left, suffixLen, false);
            }
            else

            {
                return HideSensitiveInfo(email);
            }
        }
    }
}
